The financial and economic arguments against Scottish independence are "overwhelming", a leading bank warned as it compared a Yes vote to the mistakes which led to the Great Depression of the 1930s.

In one of the starkest warnings yet issued by a financial institution, the chief economist at Deutsch Bank David Folkerts-Landau said voters and politicians had failed to grasp the potential severity of the negative consequences of separation.

He said he found it "incomprehensible" that Scots were even contemplating withdrawal from the United Kingdom, and pointed to the "recessions, higher taxes, lower public spending and higher interest rates" that had afflicted nations seen as potentially heading for the eurozone exit.

But the Scottish Government accused him of failing to take into account Scotland's "strong fiscal position", and said it would start life as an independent nation "from stronger economic foundations than any other nation in history".

In a highly-critical analysis of the prospects of independence, Mr Folkerts-Landau said: "Everyone has the right to self-determination and to exercise his or her democratic rights.

"But there are times when fundamental political decisions have negative consequences far beyond what voters and politicians could have imagined. We feel that we are on the threshold of one such moment.

"A Yes vote for Scottish independence on Thursday would go down in history as a political and economic mistake as large as Winston Churchill's decision in 1925 to return the pound to the Gold Standard or the failure of the Federal Reserve to provide sufficient liquidity to the US banking system, which we now know brought on the Great Depression in the US.

"These decisions - well-intentioned as they were - contributed to years of depression and suffering and could have been avoided had alternative decisions been taken."

But a spokesman for Scottish Finance Secretary John Swinney said: "With a Yes vote on Thursday, Scotland will become independent from stronger economic foundations than any other nation in history.

"Scotland is one of the world's wealthiest nations, with wealth per head higher than France, Japan and the rest of the UK - however for far too many people it doesn't feel that way.

"We already have well established institutions, solid economic foundations and according to the Financial Times will start life as an independent country from a strong fiscal position.

"This report would appear not to take account of any of that, at a time when more and more people in Scotland are waking up to the fact that we can, we should and we must vote Yes for a more prosperous country and a fairer society."

The paper concluded: "The economic and financial arguments against independence are overwhelming.
"But we prefer to conclude by marvelling at the 300 years in which everyone has benefited from Scotland being part of the union.
"The free movement of people has allowed greater innovation as network effects become multiplied. These can be seen, for example, in world-class universities on both sides of the border and in the spillover effect northward of London's financial centre status.
"Scotland has been able to punch above its weight via the platform of the UK and associated global trade and economic relationships. Finally, Scots have benefited from the sharing of fiscal and monetary risk.
"To end this relationship is simply a wrong turn."
Scotland would not automatically inherit the "stability and certainty" which had been provided by Whitehall and the Bank of England and there would be doubts until it could demonstrate "a tried and tested ability to govern and administer a modern economy", it said.
And keeping the pound as part of a currency union would mean Scotland becoming "a slave" to UK interest rates and forced to "severely tighten fiscal policy to establish credibility and to have the resources to underwrite the financial system".
The analysis added: "Without control of monetary policy, the Scottish Government would be unable to monetise or inflate away its debt.
"Scotland would therefore have to engage in severe austerity, either by cutting public spending or raising taxes or both, to establish fiscal credibility. In the meantime, Scottish interest rates would also rise."
It dismissed as "wishful thinking" the idea that Scotland could replicate the model of its Nordic neighbours.
"Most importantly, the world as it is evolving in the 21st century is a highly uncertain place with unstable geopolitics and a stressed economic and financial outlook," Mr Folkerts-Landau concluded.
"Why anyone would want to exit a successful economic and political union with a G5 country - a union which another part of Europe so desperately seeks to emulate - to go it alone for the benefit of... what exactly, is incomprehensible to this author."
Labour former prime minister Gordon Brown said: "The eyes of the world are on Scotland and the world is warning us.
"And never have so many warnings been given by so many, on so many occasions about the damage that separatism would cause.
"Just this evening one of the world's biggest banks joined the chorus of voices and said that a Yes vote for Scottish independence on Thursday would go down in history as one of the biggest political and economic mistakes in a century.
"The world is warning us that a Yes vote will see Scotland fall through an economic trap door. A trap door from which we could never escape."